The present invention relates to an energy dispersion-type X-ray detector utilized in energy dispersion-type X-ray analyzers and X-ray analyzers fitted with electron microscopes.
With energy dispersion-type fluorescent X-ray analyzers of the related art, selections are made as to whether to give priority to resolution or to count rate by utilizing an Si semiconductor detector with superior energy resolution and then switching over the time constant of a count circuit. However, there are no fluorescent X-ray analyzers capable of utilizing high resolution information to perform measurements at a high count rate, i.e. to take measurements with a high degree of precision over a short period of time.
The energy dispersion detector has a detection performance whereby the resolution and the count rate conflict with each other. Typically, when the device thickness and surface area of the sensor are increased in order to increase the count rate, the resolution either deteriorates or does not function at all.
In the related art, when elemental analysis or thin film measurements are carried out using a fluorescent X-ray analyzer, and the sample is not as-yet known, qualitative analysis is required. This situation requires a high resolution spectrum where each peak overlaps as little as possible, and a silicon drift chamber or semiconductor detector is therefore used. Conversely, in the case of quality management when measuring thin films, or cases where the structural composition is already known from the point of view of quality management and it is only wished to perform composition measurements, then proportional counter tubes having high count rate characteristics are used with the aim of keeping statistical errors regarding the strength of the X-rays small. However, after performing qualitative analysis using a high-resolution system in order to identify as yet unknown samples and implement high-precision measurements, it is necessary to perform the measurements again using a high resolution system taking the identified element as foreseeable information.
An energy dispersion-type detector is prepared where a sensor with a low count rate but with a superior energy resolution and a sensor with poor energy resolution but with a superior count rate are positioned in a juxtaposed manner. A method is then adopted where a signal for the sensor with superior energy resolution is utilized as foreseeable information in quantitative analysis and then utilized in qualitative analysis, and a signal for the sensor with a superior count rate is utilized in quantitative analysis. The latter stage of the sensors comprise individual preamplifiers, linear amplifiers, and pulse height analyzers, and processing is performed on spectrums in both a qualitative and quantitative manner using a common control and computing unit. This means that high resolution spectra for use in qualitative analysis and high count rate spectra for use in quantitative analysis can be obtained simultaneously in a short period of time.